Lamp



Feb. 7, 1928. 1,658,309

M. J. RITTERRATH LAMP Filed Sept. 27. 1926 2 Sheets-Sheet 1 M. J. RITTERRATH LAMP Filed Sept. 27. 1926 2 Sheets-Sheet. 2

Patented Feb. 7, 1928.

Parent OFFICE.

Max J. nrrrnnnerrr, ont'os Antennas, 'canrronivm.

LAMP,

Application filed September 27, 1926. Fcrial No. 137,901.

This invention relates to lamps, and is especially applicable to lamps of a charactor using an electric current as the source of illuminating power. p t

The invention is especially valuable when it is desired to employ an electric filament lamp or incandescent bulb as the light source.

One important use of the invention is in' outdoor illumination and, 7 more especially, illumination of the character in which 'a portion of the lightrays are projected downwardly, to illuminate the roadway, and another po-rtion of the light rays are projected the, lamp housing] i one oftheprincipal objects of the invent-ioii is toilluminate the entire lamp housing. Another important object is to eitect the iupwardly, to illuminate the upper portion or illumination otthe lamp housing without the casting of any shadow within the upper portion thereof. v

' .A further object is to effect the foregoing objects by the use of a simply constructed reflector.

A still further object is to effect deflection of the upwardly directed light raysin such a manner as to cause said light rays to traverse the entire zone within the lamp housing above the reflector so as to avoid the cast ing of a shadow by the reflector on the light transmitting root of thelamp housing The accompanying drawings illustrate the invention.

Figure 1 is an elevation of a lamp constructed in accordance with the provisions of this invention, the lamp housing being partially broken away to disclose the illuminant and the reflector.

Figure 2 is a reduced plan view of the reflee-tor shown in Fig 1, together with its supporting brackets.

Figure 3 is an enlarged vertical section of the reflector on the line indicated by 3-8, Fig. 2. r

Figure 1 is an enlarged sectional detail showing a fragment of the reflector and lamp housin "together with one of the brackets for supporting the reflector. I

I The lamp housing is' indicated in general at ofland may he of any suitable construction. In this instance, it is similar in construction to those atpresent employed to a large extent in city street illumination, and comprises a metal'base' 6, a metal top 7 an intermediate metal ring or band 8, metal ribs 9 connectingthe base 6 and band 8, and

metal ribs ltlconnecting the top 7 and'band 8. V The housing also comprises light-transmitting panes 11 interposed between the ribs 9, and light transmitting panes12 interposed between the ribslO. It will thus be seen that a large part otthe upper portion of the housing is light-transmitting, as well as the lower portion. K 1 i Supported'in any suitable manner within the lower portion 'otthe housing -is an illuminant 13. The supporting means for the illuminant are not illustrated,"noris it necessary to desc'ibe them in detail herein as the construction of said supporting means is'well-understood in this art and does not have'any' bearing upoirtheinvention. In the instance shown iii the drawings, the illuminaut'13 is a 'lilainent orincandescent b'ulhot a type commonly'employ'ed at-present, preferably a tungsten gas electric bulb. The illuminant 13 is positioned below the level of the band 8, preferably about twothirds of the distance from the base 6 tothe band 8. I

Suitably supported atapproximately the level of the band 8 is a reflector, which is indicated in general by the character 1 14, and this reflector is'constructed as follows: The reflector has an annular reflecting'face 15 which extends horizontally and may be of any desired curvature radially of the reflector. In this particular instance, the curvature of the face 15 is upwardly concave,

depending somewhat on the height that thelamp is to be placed above the street; and the size of areathat it is desired to i1luminate by the downwardly directed lightrays. The reflecting face 15 is positioned in a relation to the illuminant to reflect a portion of the light radiations downwardly and outwardly through the lower lighttransniittinp portion of the'housing. The reflector is provided with an orifice 16, and: this orifice may be located in any suitable partof the reflector.- In this particular instance the orifice '16 is centrally of the reflector and terminates the reflecting face 15 inwardly. Projecting from the marginal wall of the orifice 16 is a reflecting face or faces 17. In this particular instood that it may he discontinuous, if desired, so as to break up the face 17 into a plurality of faces. The reflecting face 17, in this instance, projects upwar lly from the inner margin of the reflecting face 15, and also extends inwardly at an angle. The reflecting face 17 may be of any suitable shape for accomplishing the purpose for which it isintended and, in this instance, is frustroconical.

The size of the orifice 16 and the relation ofthe orifice and the illuminant and said refleeting face 17 is such that the reflecting face 1'? reflects another portion of the light radiations upwardly and outwardly through all of the upper light-transmitting portion of the housing that lies outside of the path of the direct rays projected by the illuminant through the orifice, thus insuring against thereflector casting a shadow upon the upper light-transmitting portion of the housing.

It willbe clear from the foregoing that .some of the upwardly projected light rays 1 will pass unobstructed through the orifice 16 into that portion of the lamp housing above the reflector, and that other upwardly projected light rays will impinge upon the reflecting face 17 and be diverted so as to traverse an annular zone lying within the housing above the reflecting face 15.

The supporting means for the reflector, in the present instance, comprises a pair of brackets 18. Each bracket is constructed as follows: Each bracket has a U-shapedportion 19 of which the intermediate leg e2;- tends for a short distance beneath the refleeting face 15, the end legs of the U-shaped portion passing through holes 20 located in the reflecting face 15 near the periphery thereof. Connecting with the ends of the U-shaped portion 19 are downwardly projecting angular arms 21 which removably engage in a socket or sockets 22 formed in the upper face of an inward projection or projections 23 of the band 8. Thus the retlector is simply suspended so as to avoid the casting of shadows by the suspension means, and so as to facilitate placing of the reflector in the housing and removal of the reflector therefrom.

The invention described above functions as follows: Referring particularly to Fig. 3, it will be seen that a portion a of the light radiation is reflected by the reflecting face 15 downwardly, so as to illuminate the lower portion of the lamp housing and the street area adjacent to the lamp. It will also be seen that another portion Z) of the light radiation passes without obstruction upwardly through the orifice 16 into the annular Zone above the reflector 15 that would be in shadow if the orifice 16 were not provided in the reflector. Furthern'iore, it will be seen that another portion a of the light radiation is reflected by the reflecting face 17 so as to be diverted almost horizontally into the annular zone lying above 1H8 reflecting face 15, and especially into that portion of the Zone that would be in shadow if the reflecting face 17 were omitted, even though some of the light radiations are permitted to pass through the orifice 16, as mentioned above. The portions 5, c of the lightradiations illuminate that portion of the lamp housing above the band 8. and whate er foliage or other objects may be in the path of the light radiations transmitted by the members 12.

From the foregoing, it will be readily understood that I have succeeded in illuminating the lamp housing to best advantage so as to avoid the casting of shadows upon the light-transmitting members of the housing. and that this result has been secured by a comparatively simple construction. Thus, the reflector may be furnished, if desired, as an inexpensive attachment for lamp housings that are already in service, it merely being necessary to remove the special refractory shades now employed around the illuminant, and to then place the reflector 14 in place in the manner shown in Fig. 1.

I claim I A lamp comprising a housing provided with upper and lower light-transmitting portions, an illuminant within the lower portion of the housing, and a reflector in the housing between the illuminant and the upper light-transmitting portion. provided with a horizontally extending reflecti g face positioned in relation to the 'lluminant to refleet a portion of the light r; diati u down wardly and outwardly through the lower ightransniitting portion, the reflector provided with an orifice and with a reflecting ace adjacent to the orifice, the size of the orifice and the relation of the orifice and illumin-ant and last mentioned reflecting face being such that said last mentioned rellecting face reflects another portion of the light radiations upwardly and outwardly through all of the upper light-tirensmitting portion that lies outside of the path of the direct rays projected by the illuminant through the orifice.

Signed at Los Angeles, Culiiornia,this 17 day of Sept. 1926.

MAX J. RETTERRATII. 

